Method for recycling positive electrode material generated as process waste

Abstract

The present invention includes: a current collector separation step of separating a current collector and a positive electrode active material layer by treating a positive electrode, determined to be defective in a battery manufacturing process, with an organic solvent; and a drying step of performing heat treatment on the positive electrode active material layer separated from the current collector, and the present invention enables effectively recycling the positive electrode material determined to be waste in the battery manufacturing process.

Description

Method for recycling cathode materials generated as process waste

[0001] The present invention relates to a method for recycling cathode materials generated or determined as process waste during the battery manufacturing process.

[0002] End-of-life batteries (EOL-Batteries) are typically discarded. The process of disposing of batteries leads to the release of various hazardous substances and the loss of valuable metals. To address these issues, research is underway into technologies for recycling end-of-life batteries.

[0003] Meanwhile, cathode material waste is generated in various forms during the battery manufacturing process. During the battery manufacturing process, electrodes and batteries are inspected in various ways. If the inspection results indicate a defect, the battery is typically discarded. Existing research has focused on technologies for recycling batteries that have reached the end of their useful life, and research on the recycling of cathode materials, which are generated as waste during the battery manufacturing process, remains insufficient.

[0004] Therefore, there is a need for a technology that recycles cathode materials determined to be waste during the battery manufacturing process in an environmentally friendly and efficient manner.

[0005] In order to solve the problems of the prior art as described above, the present invention aims to provide a method for effectively recycling or reusing cathode materials determined to be waste during the battery manufacturing process.

[0006] In order to solve the above-mentioned problem, in one embodiment, a method for recycling a cathode according to the present invention includes a current collector detachment step of treating a cathode determined to be defective during a battery manufacturing process with an organic solvent to separate a current collector and a cathode active material layer; and a drying step of performing heat treatment on the cathode active material layer separated from the current collector.

[0007] In one embodiment, the positive electrode recycling method includes, prior to the current collector detachment step, a defect determination step for determining whether at least one of the electrode and the battery is defective during the battery manufacturing process. After the defect determination step, the electrode or battery determined to be defective is subject to recycling. Specifically, the electrode is a positive electrode, and specifically, the electrode is a lithium secondary battery.

[0008] In one embodiment, the defectiveness determination step includes, if the battery is determined to be defective, the steps of disassembling the outer case of the battery; separating the electrode assembly into a positive electrode, a negative electrode, and a separator; and washing the separated positive electrode.

[0009] In another embodiment, the collector detachment step includes an organic solvent immersion treatment step of immersing the positive electrode in an organic solvent; and an ultrasonic detachment treatment step of applying ultrasonic waves.

[0010] The above organic solvent immersion treatment step and the above ultrasonic desorption treatment step are performed together in a single process. In the present invention, it is not excluded that the ultrasonic desorption treatment step may be performed before or after the organic solvent immersion treatment step.

[0011] Specifically, in the organic solvent immersion treatment step, the organic solvent includes at least one selected from the group consisting of N-methyl-2-pyrrolidone (NMP), acetone, ethanol, propylene carbonate, ethyl methyl carbonate, ethylene carbonate, and dimethyl carbonate. For example, the organic solvent includes N-methyl-2-pyrrolidone (NMP). In addition, the organic solvent immersion treatment step can be performed at a temperature of 15 to 50°C, a temperature of 15 to 30°C, and specifically, a temperature of 25°C.

[0012] The above ultrasonic separation treatment step can be performed by applying ultrasonic waves in the range of 20 to 200 KHz for 5 to 60 minutes.

[0013] The above drying step can be performed at a temperature of 50 to 300°C for 10 to 120 minutes.

[0014] In one embodiment, the component obtained through the drying step is a mixture of a positive electrode active material and a conductive material.

[0015] As another example, the battery to be recycled in the present invention is a lithium secondary battery, and specifically, a medium- to large-sized lithium secondary battery.

[0016] The present invention can effectively recycle or reuse cathode materials determined to be waste during the battery manufacturing process.

[0017] Figure 1 is a schematic diagram showing the cross-sectional structure of a cylindrical battery.

[0018] Figure 2 is a flowchart of a positive electrode recycling process according to one embodiment of the present invention.

[0019] Figure 3 is a flowchart of a positive electrode recycling process according to another embodiment of the present invention.

[0020] Figure 4 is a flowchart of a positive electrode recycling process according to another embodiment of the present invention.

[0021] The present invention can be modified in various ways and has many embodiments, and specific embodiments will be described in detail in the detailed description.

[0022] However, this is not intended to limit the present invention to a specific embodiment, but should be understood to include all modifications, equivalents, or substitutes included in the spirit and technical scope of the present invention.

[0023] In the present invention, it should be understood that terms such as “include” or “have” are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0024]

[0025] Hereinafter, the present invention will be described in more detail.

[0026]

[0027] The positive electrode recycling method according to the present invention includes a current collector detachment step of treating a positive electrode determined to be defective during the battery manufacturing process with an organic solvent to separate a current collector and a positive electrode active material layer; and a drying step of performing heat treatment on the positive electrode active material layer separated from the current collector.

[0028] Specifically, in the process of manufacturing a secondary battery, a process of inspecting the electrode or battery is performed for each process. The present invention provides a method for effectively recycling a positive electrode classified as process waste. In the present invention, a current collector and a positive electrode active material layer are separated using an organic solvent. Specifically, the positive electrode is immersed in a storage tank containing an organic solvent. This dissolves the binder component dispersed within the positive electrode active material layer, and separates the active material layer component from the current collector. In addition, when the separated positive electrode active material layer is removed by drying to evaporate the solvent, only the solid component remains. For example, the remaining solid component is a mixture of the positive electrode active material and a conductive agent.

[0029] The present invention includes a defect determination step, prior to the current collector detachment step, for determining whether at least one of the electrode and the battery is defective during the battery manufacturing process. In the present invention, the defect determination step includes the entire process of manufacturing the electrode. After the defect determination step, the electrode or battery determined to be defective is subject to recycling. The electrode is specifically a positive electrode, and the electrode is specifically a lithium secondary battery.

[0030] In one embodiment, the defect determination step is a step for determining whether the electrode is defective. The electrode defect determination step includes, for example, a method for inspecting the presence of surface cracks through vision inspection, a method for inspecting the loading amount through weight measurement, etc.

[0031] In another embodiment, the defect determination step is a step for determining whether the electrode assembly is defective. For example, in the case of a pouch-shaped battery, this includes a method for performing a vision inspection to determine whether there is a mismatch in the laminated structure of the positive electrode, separator, and negative electrode. Alternatively, in the case of a cylindrical or square battery, this includes a method for performing a vision inspection of the winding state of a coiled jelly-roll electrode assembly.

[0032] In another embodiment, the defect determination step is a step for determining whether a battery is defective. Specifically, the step includes inspection for weld defects between the electrode tab and the electrode lead (including vision inspection, low voltage inspection, or ultrasonic application inspection), initial charge / discharge efficiency inspection, and battery life / efficiency inspection.

[0033] In one embodiment, the defectiveness determination step includes, if the battery is determined to be defective, the steps of disassembling the outer case of the battery; separating the electrode assembly into a positive electrode, a negative electrode, and a separator; and washing the separated positive electrode.

[0034] If the battery is sealed, the outer case of the battery is removed. This can be done using a punch press or waterjet cutter. The electrode assembly is separated into the positive electrode, negative electrode, and separator, which can then be recycled or disposed of individually. The separated positive electrode is then washed to remove the electrolyte. Washing methods include, for example, using distilled water.

[0035] In one embodiment, the collector detachment step includes an organic solvent immersion treatment step of immersing the positive electrode in an organic solvent; and an ultrasonic detachment treatment step of applying ultrasonic waves.

[0036] The organic solvent immersion treatment step and the ultrasonic desorption treatment step are performed together in a single process. In the present invention, the ultrasonic desorption treatment step may be performed before or after the organic solvent immersion treatment step. From a process efficiency perspective, it has been experimentally confirmed that it is advantageous to perform the organic solvent immersion treatment step and the ultrasonic desorption treatment step together in a single process.

[0037]

[0038] The organic solvent immersion treatment step is to remove the binder component by immersing the positive electrode in an organic solvent. Specifically, in the organic solvent immersion treatment step, the organic solvent includes at least one selected from the group consisting of N-methyl-2-pyrrolidone (NMP), acetone, ethanol, propylene carbonate, ethyl methyl carbonate, ethylene carbonate, and dimethyl carbonate. For example, the organic solvent includes N-methyl-2-pyrrolidone (NMP). In addition, the organic solvent immersion treatment step can be performed at a temperature of 15 to 50°C, a temperature of 15 to 30°C, and specifically, a temperature of 25°C.

[0039] The above ultrasonic separation treatment step can be performed by applying ultrasonic waves in the range of 20 to 200 kHz for 5 to 60 minutes. Specifically, the conditions for applying the ultrasonic waves can be performed under conditions of a frequency of 120 to 200 kHz and an output of 200 to 600 W. In addition, the ultrasonic wave application time can be adjusted in the range of 5 to 60 minutes, 5 to 30 minutes, or 10 to 20 minutes. The ultrasonic wave application time includes cases where ultrasonic waves are applied intermittently or periodically as well as cases where ultrasonic waves are applied continuously within the corresponding time.

[0040] The drying step can be performed at a temperature of 50 to 300°C for 10 to 120 minutes. The drying step includes both a direct drying method using a heating wire or the like and an indirect drying method using hot air. For example, the drying step in the present invention can be performed by hot air drying. Specifically, the drying step in the present invention can be performed for 30 to 80 minutes by supplying hot air at a temperature range of 100 to 150°C. The conditions for performing the drying step in the present invention can be adjusted depending on the state of the electrode or battery. However, the present invention performs the drying step at a relatively low temperature range and does not require high-temperature heat treatment. This can reduce process costs and energy costs, and prevent deformation or loss of the positive electrode material during the recycling process.

[0041] The above drying step is intended to remove the organic solvent remaining within the separated positive electrode active material layer. For example, the drying step can be performed under conditions that volatilize the organic solvent, N-methyl-2-pyrrolidone (NMP).

[0042] In one example, the component obtained through the drying step is a mixture of a positive electrode active material and a conductive material. The positive electrode active material and the conductive material can be separated through an additional process. Alternatively, the positive electrode active material and the conductive material can be reused without being separated. The process of separating the positive electrode active material and the conductive material can be performed by physical methods. For example, particle size separation using a sieve can be used to separate the components. This method utilizes the difference in particle size between the active material particles and the conductive material particles to physically remove the conductive material particles.

[0043]

[0044] The battery to be recycled in the present invention is a lithium secondary battery, and specifically, a medium- to large-sized lithium secondary battery. The lithium secondary battery may include an electrode assembly including a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode; a non-aqueous electrolyte that impregnates the electrode assembly; and an external case that houses the electrode assembly and the non-aqueous electrolyte.

[0045] The above positive electrode includes a positive electrode active material layer formed on a positive electrode current collector. The positive electrode active material layer includes a positive electrode active material, a binder, a conductive agent, and the like, and may further include a positive electrode additive commonly used in the art, if necessary.

[0046] The positive electrode active material may be a lithium-containing oxide, which may be the same or different. As the lithium-containing oxide, a lithium-containing transition metal oxide may be used.

[0047] For example, the lithium-containing transition metal oxide is Li x CoO2(0.5 <x<1.3), Li x NiO2(0.5 <x<1.3), Li x MnO2(0.5 <x<1.3), Li x Mn2O4(0.5 <x<1.3), Li x (Ni a Co b Mnc )O2(0.5 <x<1.3, 0<a<1, 0<b<1, 0<c<1, a+b+c=1), Li x Ni 1-y Co y O2(0.5 <x<1.3, 0<y<1), Li x Co 1-y Mn y O2(0.5 <x<1.3, 0≤y<1), Li x Ni 1-y Mn y O2(0.5 <x<1.3, O≤y<1), Li x (Ni a Co b Mn c )O4(0.5 <x<1.3, 0<a<2, 0<b<2, 0<c<2, a+b+c=2), Li x Mn 2-z Ni z O4(0.5 <x<1.3, 0<z<2), Li x Mn 2-z Co z O4(0.5 <x<1.3, 0<z<2), Li x CoPO4(0.5 <x<1.3) 및 Li x FePO4(0.5 <x<1.3)로 이루어진 군으로부터 선택되는 어느 하나 또는 이들 중 2종 이상의 혼합물일 수 있으며, 상기 리튬 함유 전이금속 산화물은 알루미늄(Al) 등의 금속이나 금속산화물로 코팅될 수도 있다. 또한, 상기 리튬 함유 전이금속 산화물 외에 황화물(sulfide), 셀렌화물(selenide) 및 할로겐화물(halide) 등도 사용될 수 있다.

[0048] The positive electrode according to the present invention can be applied to various types of lithium secondary batteries, but is preferably utilized in high-output batteries. The positive electrode active material layer of the present invention is applied to a high-nickel content (High-Ni) NCM battery.

[0049] In a specific example, the positive electrode active material layer according to the present invention includes an active material component having a structure represented by the following chemical formula 1.

[0050] [Chemical Formula 1]

[0051] Li x (Ni a Co b Mn c )O2

[0052] (0.5 <x<1.3, 0.3<a<1, 0<b<0.5, 0<c<0.5, a+b+c=1)

[0053] In the above chemical formula 1, the a value is greater than 0.3, 0.6 or more, and specifically, 0.8 or more. In the above chemical formula 1, when the a value increases, the b value and / or the c value decrease within a range satisfying the above chemical formula 1. Through this, the positive electrode for a lithium secondary battery according to the present invention is applied to a high-nickel content (High-Ni)-based NCM secondary battery. The NCM secondary battery is, for example, an NCM 622 or NCM 811 lithium secondary battery.

[0054] The current collector used for the positive electrode may be any metal with high conductivity, to which the positive electrode active material slurry can readily adhere, and which is non-reactive within the voltage range of the electrochemical device. Non-limiting examples of current collectors for the positive electrode include foils made of aluminum, nickel, or a combination thereof.

[0055] The above-mentioned positive electrode active material may be included in the positive electrode active material layer in a range of 94.0 to 98.5 wt%. When the content of the positive electrode active material satisfies the above range, it is advantageous in terms of manufacturing a high-capacity battery and providing sufficient positive electrode conductivity and inter-electrode material adhesion.

[0056] Any binder commonly used in the art can be used without limitation. For example, various types of binders can be used, such as poly(vinylidene fluoride-co-hexafluoropropylene), PVDF-co-HFP, polyvinylidene fluoride (PVDF), polyacrylonitrile, polymethyl methacrylate, styrene-butadiene rubber (SBR), and carboxyl methyl cellulose (CMC).

[0057] The above negative electrode includes a negative electrode active material layer formed on a negative electrode current collector. The negative electrode active material layer includes a negative electrode active material, a binder, and a conductive agent, and may further include a negative electrode additive commonly used in the art, if necessary.

[0058] The negative active material may include carbon, lithium metal, silicon, or tin. When carbon is used as the negative active material, both low-crystalline carbon and high-crystalline carbon can be used. Representative low-crystalline carbons include soft carbon and hard carbon, and representative high-crystalline carbons include natural graphite, Kish graphite, pyrolytic carbon, mesophase pitch-based carbon fiber, mesocarbon microbeads, mesophase pitches, and high-temperature calcined carbons such as petroleum or coal tar pitch derived cokes.

[0059] Non-limiting examples of current collectors used in the above negative electrode include foils made of copper, gold, nickel, or copper alloys, or combinations thereof.

[0060] Additionally, the cathode may include a conductive material and a binder commonly used in the field.

[0061] In the present invention, the separator may be any porous substrate used in a lithium secondary battery, and for example, a polyolefin porous membrane or non-woven fabric may be used, but is not particularly limited thereto.

[0062] Examples of the above polyolefin porous membrane include a membrane formed from a single or mixed polymer of polyolefin polymers such as polyethylene, polypropylene, polybutylene, polypentene, etc., such as high-density polyethylene, linear low-density polyethylene, low-density polyethylene, and ultra-high molecular weight polyethylene.

[0063] The above nonwoven fabric may include, in addition to polyolefin-based nonwoven fabrics, nonwoven fabrics formed from polymers such as polyethylene terephthalate, polybutylene terephthalate, polyester, polyacetal, polyamide, polycarbonate, polyimide, polyetheretherketone, polyethersulfone, polyphenyleneoxide, polyphenylenesulfide, and polyethylenenaphthalene, either singly or in combination. The structure of the nonwoven fabric may be a spunbond nonwoven fabric composed of long fibers or a meltblown nonwoven fabric.

[0064] The thickness of the porous substrate is not particularly limited, but may be 5 to 50 μm, and the pore size and pore content present in the porous substrate are also not particularly limited, but may be 0.01 to 50 μm and 10 to 95%, respectively.

[0065] Meanwhile, in order to improve the mechanical strength of the separator composed of the porous substrate and to suppress short circuits between the anode and cathode, a porous coating layer including inorganic particles and a binder polymer may be further included on at least one side of the porous substrate.

[0066] In the present invention, the non-aqueous electrolyte may include an organic solvent and an electrolyte salt, and the electrolyte salt is a lithium salt. The lithium salt may be any of those commonly used in non-aqueous electrolytes for lithium secondary batteries without limitation. For example, the anion of the lithium salt may be F - , Cl - , Br - , I - , NO3 - , N(CN)2 - , BF4 - , ClO4 - , PF6 - , (CF3)2PF4 - , (CF3)3PF3 - , (CF3)4PF2 - , (CF3)5PF - , (CF3)6P - , CF3SO3 - , CF3CF2SO3 - , (CF3SO2)2N - , (FSO2)2N - , CF3CF2(CF3)2CO - , (CF3SO2)2CH - , (SF5)3C - , CF3(CF2)7SO3 - , CF3CO2 - , CH3CO2 - , SCN - and (CF3CF2SO2)2N -It may include one or two or more of the group consisting of:

[0067] As the organic solvent included in the non-aqueous electrolyte described above, those commonly used in non-aqueous electrolytes for lithium secondary batteries can be used without limitation, and for example, ethers, esters, amides, linear carbonates, cyclic carbonates, etc. can be used singly or in combination of two or more. Among these, representative examples include carbonate compounds that are cyclic carbonates, linear carbonates, or mixtures thereof.

[0068] The injection of the above non-aqueous electrolyte may be performed at an appropriate stage during the electrochemical device manufacturing process, depending on the manufacturing process and required physical properties of the final product. That is, it may be applied prior to electrochemical device assembly or at the final stage of electrochemical device assembly.

[0069] Hereinafter, the present invention will be described in more detail with reference to drawings and the like. However, the drawings and the like are merely illustrative of the present invention, and the contents of the present invention are not limited thereto.

[0070]

[0071] Fig. 1 is a schematic diagram showing the cross-sectional structure of a cylindrical battery. Referring to Fig. 1, the cylindrical battery includes an electrode assembly having a structure in which a positive electrode (10), a negative electrode (20), and a separator (31, 32) are alternately laminated and wound in a cylindrical shape. A positive electrode tab (11) is formed on the upper end of the core of the electrode assembly, and a negative electrode tab (21) is formed on one side of the lower end of the electrode assembly. The electrode assembly is housed in a cylindrical battery case (40), and sealed by covering the upper end with a positive electrode cap while an electrolyte is injected.

[0072]

[0073] FIG. 2 is a flowchart illustrating a positive electrode recycling process according to one embodiment of the present invention. Referring to FIG. 2, first, an positive electrode inspection step (S110) is performed. The positive electrode inspection step (S110) includes, for example, a vision inspection of a positive electrode that has undergone a drying process to check for surface cracks. If the degree of surface cracks exceeds a standard, the positive electrode is determined to be defective. Alternatively, the positive electrode inspection step (S110) includes, for example, a weight inspection of the positive electrode to determine whether the positive electrode is defective. If the positive electrode inspection step (S110) is determined to be normal, the positive electrode is transferred to the battery manufacturing process.

[0074] The positive electrode judged to be defective in the above positive electrode inspection step (S110) undergoes an organic solvent immersion treatment step (S121), which is a step of immersing the positive electrode in an organic solvent, i.e., NMP solvent. The organic solvent immersion treatment step (S121) is performed for 30 minutes at room temperature.

[0075] Then, the anode undergoes an ultrasonic desorption treatment (S122) step. The ultrasonic desorption treatment (S122) is performed for 10 minutes under conditions of 160 kHz frequency and 400 W output.

[0076] The PVDF binder present in the positive electrode is removed through the organic solvent immersion treatment step (S121) and the ultrasonic desorption treatment step (S122), and the current collector and the positive electrode active material layer are separated. The separated current collector goes through a separate current collector recycling process.

[0077] In addition, the separated active material components go through a hot air drying step (S130). The separated positive electrode active material layer has solid components separated by particle. The separated positive electrode active material layer goes through a hot air drying step (S130) in which hot air of 120°C is supplied to dry it for 60 minutes. Through the hot air drying step (S130), the NMP solvent remaining in the positive electrode active material layer is removed.

[0078]

[0079] Figure 3 is a flowchart illustrating a positive electrode recycling process according to another embodiment of the present invention. Referring to Figure 3, a positive electrode inspection step (S210) is performed. If the positive electrode inspection step (S210) is determined to be normal, the positive electrode is transferred to the battery manufacturing process.

[0080] The positive electrodes that are judged to be defective in the above-mentioned positive electrode inspection step (S210) undergo a current collector detachment step (S220). The current collector detachment step (S220) is performed by applying ultrasonic waves while the target positive electrode is immersed in an organic solvent, NMP. The current collector detachment step (S220) is performed for 20 minutes at room temperature. The ultrasonic application is performed under conditions of a frequency of 160 kHz and an output of 400 W.

[0081] Through the above-mentioned current collector removal (S220) step, the PVDF binder present in the positive electrode is removed, and the current collector and the positive electrode active material layer are separated. The separated current collector then goes through a separate current collector recycling process.

[0082] Additionally, the separated active material components undergo a hot air drying step (S230). The separated positive electrode active material layer has solid components separated into particles. The separated positive electrode active material layer undergoes a hot air drying step (S230) in which hot air is supplied at 120°C for 60 minutes.

[0083]

[0084] FIG. 4 is a flowchart illustrating a cathode recycling process according to another embodiment of the present invention. Referring to FIG. 4, a battery inspection (S310) step is performed on a battery that has been manufactured or is in the manufacturing process. The battery inspection (S310) step checks, for example, whether welding between the electrode tab and the electrode lead has been performed normally. In this case, the battery inspection (S310) step may be performed through a visual inspection, a vision inspection, or a low-voltage inspection. Alternatively, the battery inspection (S310) step may be performed through, for example, a visual inspection for electrolyte leakage in the battery, an initial charge / discharge inspection, a battery efficiency inspection, or a cycle characteristic inspection to determine whether the battery satisfies the criteria and determine whether it is defective. If the battery inspection (S310) step determines that it is normal, the battery is transferred to the next step for shipment.

[0085] Batteries judged to be defective are subjected to a casing disassembly step (S311), if necessary. This casing disassembly step (S311) can be performed using a punching press or a water jet cutter. After the casing disassembly step (S311), the positive electrode is separated from the electrode assembly. The separated positive electrode then undergoes an electrolyte removal step (S312). The electrolyte removal step (S312) can be performed, for example, by washing with distilled water.

[0086] The positive electrode from which the electrolyte has been removed undergoes a current collector desorption (S220) step. The current collector desorption (S320) is performed by applying ultrasonic waves while the target positive electrode is immersed in an organic solvent, NMP. The current collector desorption (S320) step is performed for 20 minutes at room temperature. The ultrasonic application is performed at a frequency of 160 kHz and an output of 400 W.

[0087] Through the above-mentioned current collector desorption (S320) step, the PVDF binder present in the positive electrode is removed, and the current collector and the positive electrode active material layer are separated. The separated current collector then goes through a separate current collector recycling process.

[0088] Additionally, the separated active material components undergo a hot air drying step (S330). The separated positive electrode active material layer has solid components separated into particles. The separated positive electrode active material layer undergoes a hot air drying step (S330) in which hot air is supplied at 120°C for 60 minutes.

[0089]

[0090] Although the present invention has been described above with reference to preferred embodiments thereof, it will be understood by those skilled in the art or having ordinary knowledge in the art that various modifications and changes may be made to the present invention without departing from the spirit and technical scope of the present invention as set forth in the claims to be described below.

[0091] Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the patent claims.

[0092]

[0093] The present invention is the result of research conducted through the following national research and development project.

[0094] Assignment ID: 2420005912

[0095] Assignment Number: RS-2024-00467315

[0096] Ministry Name: Ministry of SMEs and Startups

[0097] Project Management (Specialist) Agency Name: Small and Medium Business Technology Information Promotion Agency

[0098] Research Project Name: Startup Growth Technology Development (R&D)

[0099] Research Project Name: Technology for Remanufacturing Positive Electrode Materials Using Process Scrap

[0100] Project execution organization name: ABR Co., Ltd.

[0101] Research period: August 1, 2024 - July 31, 2025

[0102]

[0103] [Explanation of symbols]

[0104] 10: Bipolar

[0105] 11: Positive tab

[0106] 20: Cathode

[0107] 21: Negative tab

[0108] 31, 32: Membrane

[0109] 40: Battery case

Claims

1. A current collector detachment step in which an organic solvent is treated on a positive electrode determined to be defective during the battery manufacturing process to separate the current collector and the positive electrode active material layer; and A drying step of performing heat treatment on the positive electrode active material layer separated from the current collector; A method for recycling anodes, including:

2. In paragraph 1, Before the above-mentioned full-body detachment step, A cathode recycling method further comprising a defect determination step for determining whether at least one of the electrode and the battery is defective during the battery manufacturing process.

3. In paragraph 1, The above defect judgment step is: If the battery is judged to be defective, A step of disassembling the outer case for the above battery; A step of separating the electrode assembly into a positive electrode, a negative electrode, and a separator; and A method for recycling an anode, further comprising a step of washing the separated anode.

4. In paragraph 1, The above-mentioned full-body detachment step is: An organic solvent immersion treatment step of immersing the anode in an organic solvent; and A method for recycling anodes, comprising an ultrasonic desorption treatment step of applying ultrasonic waves.

5. In paragraph 4, The organic solvent immersion treatment step and the ultrasonic desorption treatment step are, A cathode recycling method characterized in that it is performed together in a single process.

6. In paragraph 4, In the above organic solvent immersion treatment step, A method for recycling an anode, wherein the organic solvent comprises at least one selected from the group consisting of N-methyl-2-pyrrolidone (NMP), acetone, ethanol, propylene carbonate, ethyl methyl carbonate, ethylene carbonate, and dimethyl carbonate.

7. In paragraph 4, The above ultrasonic separation treatment step is: A method for recycling an anode, characterized in that it is performed by applying ultrasonic waves in the range of 20 to 200 KHz for 5 to 60 minutes.

8. In paragraph 1, The above drying step is, A cathode recycling method characterized in that it is performed for 10 to 120 minutes under temperature conditions of 50 to 300℃.

9. In paragraph 1, The components obtained through the above drying step are: A method for recycling a cathode, characterized in that it is in a mixed state of a cathode active material and a conductive material.

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